The results of indoor test and on-site inspection indicate that as phalt modified with rubber powder performs well in improving density of pavement,anti-seepage,anti-skid,lowering noise and cost and protecting environment,which proves that it has good performance,prominent economic benefit and social benefit,worth popularizing in high temperature and rainy .

This article discusses measuring theory of subgrade compactness, structure of instrument and keys techniques based on portable computer and introduces in detail the measuring technical line, theory of the data acquisition and main functions models and characteristics of the corresponding data acquisition and process softwa.

This paper depicts the principle and technical keys of rapid and nondestructive measurement of subgrade compactness by the instantaneous impulsion method.

Theory and practice of subgrade compaction quality testing by surface wave velocity in stead of index K_(30);

Based on the laboratory tests,the influences of two subgrade compaction controlling index to the subgrade stability were compared,and a conclusion was obtained that it is feasible to control the quality of subgrae compaction by air rate.

Subgrade construction quality monitor is a light instrument specially developed for fast test of subgrade compaction quality.